Tau neutrino as a probe of nonstandard interaction

Abstract

We study the $Δ$-resonance and deep inelastic scattering contributions in the tau-neutrino nucleon scattering $ν_τ+ N \to τ^- + X$ and $\barν_τ+ N \to τ^+ + X$ in the presence of a charged Higgs and a $W'$ gauge boson. The new physics effects to the quasielastic process have been discussed in a previous work. The extractions of the atmospheric mixing angle $θ_{23}$ rely on the standard model cross sections for $ν_τ+ N \to τ^- + X$ in $ν_τ$ appearance experiments. Corrections to the cross sections from the charged Higgs and $W'$ contributions modify the measured mixing angle. We include form factor effects in the new physics calculations and find the deviations of the mixing angle. If high-energy Long Base Line experiments are designed to measure $θ_{13}$ through tau neutrino appearance, the new physics effects to $ν_τ+ N \to τ^- + X$ and $\barν_τ+ N \to τ^+ + X$ can impact the extraction of this mixing angle. Finally, we investigate the new physics effects on the polarization of the $τ^\mp$ leptons produced in $ν_τ(\barν_τ)$ nucleon scattering.

27 pages, 31 figures. Accepted for Publication in Nuclear Physics B